Device for loading data into computer processing units from a data source

ABSTRACT

A data loading device for loading data into computer processor units from a data source, the device comprising at least a first connector for connecting to the data source and provided with a PHY component, and a plurality of second connectors for connecting to the computer processor units and each provided with a respective PHY component, the first connector being connected to the second connectors by a first selector module in order to define a single down channel so as to transmit data from the first connector to each of the second connectors individually, and by a second selector module for defining a single up channel so as to transmit data in the opposite direction, the selector modules being arranged to be capable of connecting only one of the second connectors at a time to the first connector and the device including a control unit for controlling the selector modules to select which second connector to connect to the first connector.

The present invention relates to loading data into computer units.

STATE OF THE ART

Such a computer unit comprises at least one memory and a processor forprocessing data, e.g. so as to form a computer.

Data is loaded into computer units, e.g. in order to update the programscontained in the computer units or to update the data used by thecomputer units for performing the processing they are to perform.

Update data is generally contained in a data source that is usuallyformed by a computer executing data loading software. The data sourcemay also be a portable memory medium such as a memory card.

When the computer units are not very numerous, it is possible to connectthe data source directly to each unit.

Nevertheless, that is difficult to do when the units are not veryaccessible. It is then known to connect the computer units to a singledevice, such as a switch or a concentrator, to which the data source canbe connected from a location that is more easily accessible.

Furthermore, in certain sensitive applications, it is necessary to beable to update computer units, while ensuring that each computer unitreceives the data that is intended for that unit and only that data. Itis then appropriate to prevent the computer units from communicatingwith one another so as to avoid any possibility of information passingbetween them. These constraints apply in particular in the field ofaviation: the ARINC615A standard thus defines the characteristics thatneed to be complied with by systems for loading update data intoaircraft computers.

It is relatively complicated to comply with those constraints when thecomputer units are connected to a network operating with the Ethernetcommunication protocol. It should be recalled that in accordance withthe open system interconnection (OSI) model, in order to transmit datafrom one computer to another, it is necessary to apply a series oftransformations to that data, which transformations are considered as“layers” going, when sending data, from a highest level (“application”layer) to a lowest level (“physical” layer or “PHY” layer), and in theopposite direction when receiving data. Transmitting data by theEthernet protocol thus relies on obtaining the media access control(MAC) address on receiving data, i.e. decoding the data frames in orderto work back successively from the PHY layer and then to the “data link”layer in which the MAC address is encapsulated. Thus, an Ethernet switchinspects the data packets passing therethrough in order to read the MACaddress of the destination, which means that a fraudster having accessto a computer unit of the network and knowing the MAC address of anotherone of the computer units of the network would be in a position to sendmessages directly to that other unit. The only known solution lies ininstalling a protocol or a particular device for preventing certaincomputer units from communicating with one another, nevertheless theexistence of a permanent physical link between the computer units leavesa risk of that protocol being bypassed.

Documents US-A-2014/321477 and US-A-2009/303883 describe two methods ofrouting data by means of an Ethernet protocol and using MAC addressesfor routing the data.

OBJECT OF THE INVENTION

An object of the invention is to make data transfer more reliable.

SUMMARY OF THE INVENTION

According to the invention, there is provided a data loading device forloading data into computer units from a data source, the devicecomprising at least a first connector provided with a PHY component anda plurality of second connectors each provided with a respective PHYcomponent, the first connector being connected to the second connectorsby a first selector module in order to define a single down channel soas to transmit data from the first connector to each of the secondconnectors individually, and by a second selector module for defining asingle up channel so as to transmit data in the opposite direction, theselector modules being arranged to be capable of connecting only one ofthe second connectors at a time to the first connector and the deviceincluding a local control unit for controlling the selector modules toselect which second connector to connect to the first connector.

The data source is then connected to the first connector and thecomputer units are connected to the second connectors. Associating eachconnector with a PHY component enables that connector to be identifiedby means of the identifier that is allocated to each PHY component, andthus enables the computer unit to which it is connected to beidentified. The local control unit makes it possible to select thesecond connector and thus the computer unit that is to be connected tothe first connector, and thus to the data source. The data loadingdevice therefore has no need to know the MAC address of the destination,since the destination can be selected from the identifiers of the PHYcomponents in each of the connectors. There is therefore no need todecode the data and then recode it in order to route it: the data iscopied unchanged from one PHY component to another. The PHY componentsthus enable each of the computer units that are connected to the secondconnectors to be connected to the data source that is connected to thefirst connector, and in combination with the selector modules, theyprevent any direct link between the computer units. Specifically, byconnecting to one of the second connectors, it is impossible to access acomputer unit that is connected to a different second connector, sincethere is no physical link between them.

According to a particular characteristic of the invention, the devicecomprises a chassis having mounted thereon the selector modules, thefirst connector, and the second connectors, the control unit comprisinga local control unit and a remote control unit connected by a cable tothe local control unit and provided with a man/machine interface.

Under such circumstances, and advantageously:

-   -   the remote control unit comprises a housing provided with an        external connector directly connected to the first connector of        the loading device in order to connect the data source to the        first connector via the external connector of the remote control        unit; and/or    -   the remote control unit comprises a memory storing a table        associating each second connector with at least one        characteristic of a computer unit connected to the second        connector; and preferably, the characteristic is a data transfer        rate and the table is loaded into a memory of the local control        unit that is arranged, on establishing an up channel and a down        channel with one of the second connectors, to control the PHY        component of the second connector so that it operates at the        stored transfer rate or at an automatically negotiated rate;        and/or    -   the remote control unit and the local control unit are        programmed respectively to form a master unit and a slave unit;        and/or    -   the remote control unit and the local control unit are        programmed to communicate with each other by means of the        internet protocol (IP) and the user datagram protocol (UDP), the        remote control unit and the local control unit having static IP        and MAC addresses; and/or    -   the remote control unit is arranged to switch off the power        supply to the local control unit in at least one particular        situation; and/or    -   the remote control unit and the local control unit are arranged        in such a manner that the local control unit cannot be powered        unless the remote control unit is powered.

According to other particular characteristics, optionally combined withthe above and/or with one another:

-   -   the control unit is arranged to put the PHY components of the        second connectors that are not connected to the first connector        into an inactive state and to be able to put into an active        state only that one of the second connectors that is connected        to the first connector;    -   the selector modules are formed by a field programmable gate        array (FPGA) circuit having defined therein buses that are        compatible with the reduced media-independent interface (RMII)        standard or connecting the selector modules to the first        connector;    -   the device includes a test module for testing the links between        the first connector and the second connectors; and the test        module advantageously comprises: a multiplexer having an output        connected to an input of the first selector module, a first        input connected to the first connector, and a second input        connected to a signal generator; a demultiplexer having an input        connected to an output of the second selector module, a first        output connected to a signal analyzer, and a second output        connected to a first input of a multiplexer having a second        input connected to the signal generator and an output connected        to the first connector (in such a manner as to avoid creating a        data path between the up and down channels), the first connector        also being connected by its up channel to the signal analyzer;        and    -   an independent additional safety function may be implemented in        order to force the PHY components of the second connectors to be        unpowered if two PHY components of the second connectors are        detected as being active simultaneously. The control unit may        also be arranged to issue a warning if it detects that two PHY        components of the second connectors are activated        simultaneously.

Other characteristics and advantages of the invention appear on readingthe following description of a particular, non-limiting embodiment ofthe invention.

SUMMARY OF THE FIGURES

Reference is made to the accompanying drawings, in which:

FIG. 1 is a diagram showing a device of the invention connected to adata source and to computer units;

FIG. 2 is a diagram analogous to the diagram of FIG. 1 , showing thedata streams in a nominal mode of operation;

FIG. 3 is a diagram analogous to the diagram of FIG. 1 , showing thedata streams in a test mode of operation;

FIG. 4 is a diagram of a variant embodiment of the remote control unit;and

FIG. 5 is a diagram showing a device making it possible to avoid aplurality of PHY components of the second connectors being in theiractivation state simultaneously.

DETAILED DESCRIPTION OF THE INVENTION

With reference to FIGS. 1 to 3 , the data loading device of theinvention is described herein with reference to updating computer units100 of an aircraft, and more particularly in this example of anairliner. The computer units 100 comprise in particular computersinvolved in the operation of the aircraft, e.g. flight computers andnavigation computers, and computer units that are dedicated toentertaining the passengers of the aircraft, and for examplevideo-on-demand servers. The data that is updated may comprise, by wayof example: a new version of a program; a correcting “patch”; updatedvalues for parameters; There are N computer units 100 (with only threebeing shown in the figures) and they are referenced 100 _(i) in order todistinguish them from one another, where i varies over the range 1 to N.

In conventional manner, each computer unit 100 _(i) comprises at leastone memory and a processor for executing a program contained in thememory in order to process data stored in the memory and/or data comingfrom members, such as sensors, that are connected to the computer unit.In conventional manner, each computer unit 100 _(i) includes a connector101 provided with a PHY component. It should be recalled that a PHYcomponent is an analog-to-digital converter and it forms part of thephysical layer of the OSI model.

The data for updating the computer units 100 _(i) is stored in a datasource, which, in this example, is constituted by a computer unit 200that comprises in conventional manner at least one memory containing theupdate data and a processor for executing a program for loading datacontained in the memory in order to enable the update data to be loadedinto the computer units 100 _(i) for which said update data is intended.In conventional manner, the computer unit 200 includes a computerprovided with a PHY component 201. The functions of the computer unit200 can be taken to be equivalent to those of the PSLs of conventionalsystems for updating aircraft computers.

The computer units 100 _(i) are connected to the computer unit 200 via adata loading device of the invention. The functions of the data loadingdevice can be considered to be equivalent to those of the data loadingrouting boxes (DLRBs) of conventional updating systems for aircraftcomputers.

This loading device, given overall reference 1, comprises:

-   -   a first connector 10 provided with a PHY component;    -   a plurality of second connectors 20 _(i), where i lies in the        range 1 to N, each provided with a respective PHY component;    -   a third connector 30 provided with a PHY component;    -   a first selector module 40 for selecting a down channel between        the first connector 10 and one of the second connectors 20 _(i);        and    -   a second selector module 50 for selecting an up channel between        the first connector 10 and one of the second connectors 20 _(i).

The selector module 40 has an input connected to a first RMII bus 61 andN+2 outputs referenced 0 to N and X. The outputs 1 to N are eachconnected to the PHY component of a respective one of the secondconnectors 20 _(i) by a respective line 41; the output 0 is notconnected; and the output X is connected to the PHY component of thethird connector 30 by a line 42.

The selector module 50 has an output connected to a second RMII bus 62and N+2 inputs referenced 0 to N and X. The inputs 1 to N are eachconnected to the PHY component of a respective one of the secondconnectors 20 _(i) by a respective line 51; the input 0 is notconnected; and the input X is connected to the PHY component of thethird connector 30 by a line 52.

The selector module 40 is arranged to define a single down channel so asto transmit data from the first connector 10 to each of the secondconnectors 20 _(i) individually, and the selector module 50 is arrangedto define a single up channel so as to transmit data in the oppositedirection. The selector modules 40 and 50 are arranged so as to becapable of connecting the first connector 10 to only one of the secondconnectors 20 _(i) at a time.

The lines 41 are distinct from the lines 51; and the line 42 is distinctfrom the line 52.

The RMII buses 61 and 62 are distinct from each other and they areconnected to a test module given overall reference 70. More precisely,the first RMII bus 61 is connected to the output of a multiplexer 71having a first input connected to the first connector 10 and a secondinput connected to a signal generator 72. The second RMII bus 62 isconnected to an input of a demultiplexer 73 having a first outputconnected to a signal analyzer 74 and a second output connected to afirst input of a multiplexer 75 having a second input connected to thesignal generator 72 and an output connected to the first connector 10.The first connector 10 is also connected by its up channel to the signalanalyzer 74.

The selector modules 40 and 50 and the RMII buses 61 and 62 are formedon a field programmable gate array (FPGA) circuit.

The selector modules 40 and 50 have a control input connected to thecontrol output of a local control unit 80 arranged to control theselector modules 40 and 50 in order to select the second connector 20_(i) for connecting to the first connector 10.

For this purpose, and in conventional manner, the local control unit 80comprises at least one memory and a processor for executing a programcontained in the memory and arranged:

-   -   to control the selector modules 40 and 50 in order to select the        second connector 20 _(i) for connecting to the first connector        10;    -   to put the PHY components of the second connectors 20 _(i) that        are not connected to the first connector 10 into an inactive        state;    -   to be able to put into an active state only that one of the        second connectors 20 _(i) that is connected to the first        connector 10; and    -   to perform a test procedure on starting the local control unit        80.

In this example, the selector modules 40 and 50, the buses 61 and 62,the test module 70, the first connector 10, the second connectors 20_(i), the third connector 30, and the local control unit are all mountedon a common chassis.

In conventional manner, the control device also has a remote controlunit 90 that comprises at least one memory and a processor for executinga program contained in the memory in order to enable an operator toselect the computer units 100 _(i) that are to be updated. The memorycontains a table associating an identifier and a transfer rate of acomputer unit 100 _(i) with the second connector 20 _(i) to which thecomputer unit 100 _(i) is connected. The remote control unit 90 isprovided with a man/machine interface, specifically a screen 91 and abutton 92 for selecting options displayed on the screen 91. Thefunctions of the remote control unit 90 can be considered to beequivalent to those of the DSLU of conventional updating systems foraircraft computers.

The remote control unit 90 is connected by a cable to the thirdconnector 30 and thus to the local control unit 80. The remote controlunit 90 and the local control unit 80 are programmed to communicate witheach other by means of the IP and UDP protocols, with the remote controlunit 90 and the local control unit 80 having static IP and MACaddresses. The remote control unit 90 and the local control unit 80 areprogrammed to form respectively a master unit and a slave unit.

The program executed by the remote control unit 90 is arranged:

-   -   when the remote control unit 90 is switched on, to detect        whether the aircraft is in flight or stationary on the ground,        and if stationary on the ground to allow the local control unit        80 to be powered;    -   when the local control unit 80 is powered, to load the table in        the memory of the local control unit;    -   to display a menu on the screen 91 enabling the operator to        select the computer units to be updated and to launch a test of        the loading devices; and    -   to turn off the local control unit 80 in at least one particular        situation, specifically when the aircraft starts to move, and        more generally to prevent the local control unit 80 from being        powered unless the aircraft is stationary.

It should be observed that the remote control unit and the local controlunit are arranged in such a manner that the local control unit cannot bepowered when the remote control unit is not powered.

With reference to FIG. 2 , there follows a description of an operationfor loading data into the computer unit 100 ₂.

When the remote control unit 90 is switched on by the operator, theremote control unit 90 verifies that the aircraft is stationary, andwhere appropriate, switches on the power to the local control unit 80 inorder to load the table therein. The remote control unit 90 thendisplays a menu proposing updating the computer units 100 _(i) with thepossibility of selecting a computer unit 100 _(i) for updating. By wayof example, the operator may use the button 92 to select updating of thecomputer unit 100 ₂ and to connect the computer unit 200 to the firstconnector 10.

The remote control unit 90 then sends an instruction to the localcontrol unit 80 to link the computer unit 200 to the computer unit 100₂. The local control unit 80 returns an acknowledgment to the remotecontrol unit 90 and controls the selector units 40 and 50 so as toconnect the PHY component of the first connector 10 to the PHY componentof the second connector 20 ₂ in compliance with the content of the tablethat it has in memory. The transfer rate is set to the value thatappears in the table, or if the computer unit 100 ₂ cannot communicateat that transfer rate, a negotiation is undertaken in order to determinea lower transfer rate.

The remote control unit 90 can also be put into communication with thecomputer unit 200 if it sends the corresponding instruction to the localcontrol unit 80.

An up channel and a down channel are set up between the PHY componentsof the first connector 10 and of the second connector 20 ₂ at the storedtransfer rate or at the automatically negotiated rate.

The program of the computer unit 200 then causes update data to betransmitted.

The data paths are marked in bold in FIG. 2 .

At the end of updating the computer unit 100 ₂, the operator uses theman/machine interface to tell the remote control unit 90 either to stopupdating, or else to select a new information unit 100 _(i).

It should be observed that the loading device has no need to inspect themessages in order to route them.

It should also be observed that no physical connection is set up betweenthe second connectors 20 _(i).

With reference to FIG. 3 , there follows a description of an operationof testing the loading device 1.

On being switched on, the local control unit 80 causes a test procedureto be executed. This procedure seeks to test proper operation of thelinks between the first connector 10 and the second connectors 20 _(i).This procedure comprises two stages, namely:

-   -   verifying the links between the test module 80 and each of the        second connectors 20 _(i) in the up direction and in the down        direction; and    -   verifying the links between the test module 80 and the first        connector 10 in the up direction and in the down direction.

Verifying the link between the test module 80 and each of the secondconnectors 20 _(i) comprises the steps of:

-   -   controlling the selector modules 40 and 50 so as to connect the        test module 70 to one of the second connectors 20 _(i) (the        local control unit 80 selects the output N on the selector        module 40 and the input N on the selector module 50 in order to        connect the second connector 20 _(N) in FIG. 3 );    -   controlling the PHY component of the second connector 20 _(N) in        order to form a loop inside the loading device 1;    -   causing a signal to be issued by the signal generator 72 (the        looped path of the signal from the test module 70 to the second        connector 20 _(N) is marked bold in FIG. 3 ); and    -   verifying in the signal analyzer 74 that a signal corresponding        to the signal as issued is indeed received within a nominal        period and issuing a warning, if not.

These steps are restarted for each of the second connectors 20 _(i).

Verifying the links between the test module 80 and the first connector10 comprises the steps of:

-   -   controlling the selector modules 40 and 50 so as to prevent a        signal from passing to the second connectors 20 _(i) and the        third connector 30 (the local control unit 80 selects the output        0 on the selector module 40 and the input 0 on the selector        module 50);    -   controlling the PHY component of the first connector 10 to form        a loop inside the loading device 1;    -   causing the signal generator 72 to issue a signal (the looped        path of the signal from the test module 70 to the first        connector 10 is marked bold in FIG. 3 ); and    -   using the signal analyzer 74 to verify that a signal        corresponding to the signal as issued is indeed received within        a nominal time period, and issuing a warning, if not.

FIG. 4 shows a variant embodiment of the remote control unit 90.

In this variant, the remote control unit 90 comprises a housing providedwith a connector 93 that is connected directly to the first connector 10of the loading device 1.

The computer unit 200 is no longer directly connected to the firstconnector 10 but is connected to the connector 93 so that the computerunit 200 is connected to the first connector 10 via the connector 93 ofthe remote control unit 90.

A device is advantageously provided to ensure that a plurality of PHYcomponents of the second connectors cannot be in their activation statesimultaneously.

In a first possibility, the local control unit 80 is arranged to detectthe states of the PHY components of the second connectors 20 _(i) and toallow only one of them to be activated providing the PHY components ofthe other second connectors 20 _(i) are in their inactivated state.

In a second possibility, the local control unit 80 is arranged to detectthe states of the PHY components of the second connectors 20 _(i) and todeactivate all of the active PHY components of the second connectors 20_(i) if a plurality of them are detected as being in the activatedstate.

FIG. 5 shows that the PHY component of each second connector 20 _(i) isactivated by a signal PWREN coming from an AND gate 45 _(i) having afirst input connected to an output of a member (which output correspondsto the second connector 20 _(i) in question) and a second inputconnected to an OR gate 46 _(i) (or a NOR gate) having inputs connectedto the outputs of the member (which outputs correspond to the othersecond connectors 20 _(i) not including the second connector 20 _(i) inquestion). The member 47 also has an input set to 1 and a selectioninput i.

Thus, a PHY component of a second connector 20 _(i) can be in itsactivated state only if no other second connector has its PHY componentactivated.

Naturally, the invention is not limited to the embodiment described andcovers any variant coming within the ambit of the invention as definedby the claims.

In particular, the structure of the loading device may be different fromthat described. Thus:

-   -   the loading device need not have a test module 70;    -   the number of second connectors may be different;    -   the remote control unit need not have a connector 93 or the        remote control unit may be arranged to co-operate with data        sources of the integrated circuit card type;    -   the remote control unit and the local control unit may        communicate via some other communication protocol; and    -   the loading device need not include a remote control unit, and a        local control unit may be distinct from the remainder of the        loading device; . . . .

The loading device may optionally include an additional safety functionseeking to make the PHY components inactive when two PHY components aredetected as being in the active state simultaneously. The control unitmay optionally be arranged to detect the states of the PHY components ofthe second connectors and to issue a warning if it detects that two PHYcomponents of the second connectors are active simultaneously. By way ofexample, this warning may lead to at least one of said PHY componentsbeing inactivated, or both of them, to a failure being stored in afailure log, to loading operations being stopped while waiting for humanintervention, . . . .

The invention claimed is:
 1. A method for loading data into computerprocessor units of an aircraft from a data source, with a data loadingdevice comprising at least a first connector for connecting to the datasource and provided with a PHY component, and a plurality of secondconnectors for connecting to the computer processor units and eachprovided with a respective PHY component, the first connector beingconnected to the second connectors by a first selector module in orderto define a single down channel so as to transmit data from the firstconnector to each of the second connectors individually, and by a secondselector module for defining a single up channel so as to transmit datain the opposite direction, the first and second selector modules beingarranged to be capable of connecting only one of the second connectorsat a time to the first connector and the device including a control unitfor controlling the selector modules to select which second connector toconnect to the first connector as a function of an identifier of the PHYcomponent to which each connector is connected, the device comprising achassis having mounted thereon the selector modules, the firstconnector, and the second connectors, the control unit comprising alocal control unit and a remote control unit connected by a cable to thelocal control unit and provided with a man/machine interface, the remotecontrol unit comprising a housing provided with an external connectordirectly connected to the first connector of the loading device in orderto connect the data source to the first connector via the externalconnector of the remote control unit and the remote control unitcomprising a memory containing a table associating an identifier and atransfer rate of each computer unit connected to one of with the secondconnectors, the method comprising: when the remote control unit isswitched on by an operator, verifying that the aircraft is stationary,and where appropriate, switching on the power to the local control unitin order to load the table in the local control unit, making the remotecontrol unit display a menu proposing updating the computer units withthe possibility for the operator of selecting a computer unit forupdating, making the remote control unit send an instruction to thelocal control unit to link the selected computer unit to the datasource, making the local control unit return an acknowledgment to theremote control unit and controls the selector units so as to connect thePHY component of the first connector to the PHY component of the secondconnector corresponding to the selected computer unit in compliance withthe content of the table that it has in memory, and set the transferrate to the value that appears in the table, or if the selected computerunit cannot communicate at that transfer rate, undertake a negotiationin order to determine a lower transfer rate for setting up an up channeland a down channel between the PHY components of the first connector andof the second connector at the stored transfer rate or at theautomatically negotiated rate, causing the update data to betransmitted.
 2. The method according to claim 1, wherein the remotecontrol unit and the local control unit are programmed respectively toform a master unit and a slave unit.
 3. The method according to claim 1,wherein the remote control unit and the local control unit areprogrammed to communicate with each other by means of IP and UDPprotocols, the remote control unit and the local control unit havingstatic IP and MAC addresses.
 4. The method according to claim 1, whereinthe remote control unit is arranged to switch off the power supply tothe local control unit in at least one particular situation.
 5. Themethod according to claim 1, wherein the remote control unit and thelocal control unit are arranged in such a manner that the local controlunit cannot be powered unless the remote control unit is powered.
 6. Themethod according to claim 1, wherein the control unit is arranged to putthe PHY components of the second connectors that are not connected tothe first connector into an inactive state and to be able to put into anactive state only that one of the second connectors that is connected tothe first connector.
 7. The method according to claim 1, wherein theselector modules are formed by an FPGA circuit having defined thereinbuses that are compatible with the RMII standard or connecting theselector modules to the first connector.
 8. The method according toclaim 1, including a test module for testing the links between the firstconnector and the second connectors.
 9. The method according to claim 8,wherein the test module comprises: a multiplexer having an outputconnected to an input of the first selector module, a first inputconnected to the first connector, and a second input connected to asignal generator; a demultiplexer having an input connected to an outputof the second selector module, a first output connected to a signalanalyzer, and a second output connected to a first input of amultiplexer having a second input connected to the signal generator andan output connected to the first connector, the first connector alsobeing connected by its up channel to the signal analyzer.
 10. The methodof claim 1, wherein the selector modules are controlled to select whichsecond connector to connect to the first connector without using any MACaddress of the computer processor units.
 11. The method of claim 1,wherein update data to be transmitted are routed without decoding andrecoding them.
 12. The method of claim 1, wherein the update data to betransmitted are copied unchanged from one PHY component to another. 13.The method of claim 1, wherein each PHY component has a correspondingidentifier, and the control unit controls the selector modules bytransmitting to the identifier of the PHY component provided to one ofthe second connectors to be connected to the first connector to theselector modules.
 14. A method for loading data into computer processorunits of an aircraft from a data source, with a data loading devicecomprising at least a first connector for connecting to the data sourceand provided with a PHY component, and a plurality of second connectorsfor connecting to the computer processor units and each provided with arespective PHY component, the first connector being connected to thesecond connectors by a first selector module in order to define a singledown channel so as to transmit data from the first connector to each ofthe second connectors individually, and by a second selector module fordefining a single up channel so as to transmit data in the oppositedirection, the first and second selector modules being arranged to becapable of connecting only one of the second connectors at a time to thefirst connector and the device including a control unit for controllingthe selector modules to select which second connector to connect to thefirst connector as a function of an identifier of the PHY component towhich each connector is connected, the control unit including a testmodule comprises: a multiplexer having an output connected to an inputof the first selector module, a first input connected to the firstconnector, and a second input connected to a signal generator; ademultiplexer having an input connected to an output of the secondselector module, a first output connected to a signal analyzer, and asecond output connected to a first input of a multiplexer having asecond input connected to the signal generator and an output connectedto the first connector, the first connector also being connected by itsup channel to the signal analyzer, the method comprising: on beingswitched on, making the local control unit cause a test procedure to beexecuted, said procedure comprising: a stage of verifying the linkbetween the test module and each of the second connectors, comprisingthe steps of: controlling the selector modules so as to connect the testmodule to one of the second connectors; controlling the PHY component ofthe second connector in order to form a loop inside the loading device;causing a signal to be issued by the signal generator; and verifying inthe signal analyzer that a signal corresponding to the signal as issuedis indeed received within a nominal period and issuing a warning, ifnot, these steps being restarted for each of the second connectors; astage of verifying the links between the test module and the firstconnector comprising the steps of: controlling the selector modules soas to prevent a signal from passing to the second connectors and thethird connector; controlling the PHY component of the first connector toform a loop inside the loading device; causing the signal generator toissue a signal; and using the signal analyzer to verify that a signalcorresponding to the signal as issued is indeed received within anominal time period, and issuing a warning, if not.